Indian Institute of Technology Kharagpur (IIT-K) 2008 B.Tech Mechanical Engineering Mechanics Part -2 - Question Paper
Mechanics
1st year
Mechanical Engineering Department
Indian Institute of Technology ,Kharagpur
Both part of the paper is attached beneath.
2(b). In order to design a torsional shaft, it is required to calculate how much the shaft can be bored out while maintaining certain performance criteria. The outer diameter of the shaft is 50 mm (Fig. 2b). (a) Determine the limit on the bore diameter, d, such that the maximum shear stress does not exceed 140% of the maximum shear stress in the solid shaft under the same applied torque, (b) By assuming that the bore diameter is 35 mm determine the maximum bore length, a, such that the overall rotation of the shaft does not exceed 120% of the rotation for the solid
shaft under the same applied torque.
 |
|
Figure 2b |
(10)
|
W=wl |
 |
3(a). A simply supported beam with overhang is loaded as shown in the Figure 3a. If a = lj2, find the ratio PjW such that there is no deflection at point C. (12)
3(b). A pressure vessel is composed of a cylindrical central part with two conical frustums attached at the two ends of the cylinder as shown in Figure 3b. The cylinder has length Lj. The frustums have length L2. The semi vertical angle of each of the frustums is 0. The cones have a radius of r at the outer ends. The wall is has a thickness t which is much smaller as compared to the othei dimensions of thcrpressurc vcsse!.
Mutually opposing torques T are applied at the ends of the frustums as shown (Fig. 3b), while the pressure vessel is subjected to an axial tension F. The pressure in the vessel is p = 0.1 MPa. What are the principal stresses and maximuni shear stress at the point P lying on the outer surface of the cylinder at the location shown? L]=L2= lm, 9 = 15 deg, r = 0.25 m, t = 0.01 m. T= 30 kNm, F- 30 kN. (13)
o.isfcPa
1 m
3 m
|
Attachment: |
| Earning: Approval pending. |
